The overall aim of this proposal is to understand basic factors which influence nutrient metabolism in humans. Our approach in pursuing this aim is based on the following premises: 1. macronutrients are not eaten in isolation but rather as a mixture and therefore should be studied in this same context, 2. nutrient processing in the body will be influenced by the meatolic state of the individual, and therefore must be investigated in both the fasted and fed states and 3. nutrient processing will be influenced by gender. To achieve this aim, we will employ an experimental model that will be measure the metabolic rate of meal derived glucose and lipid in fed and fasted humans.